DESCRIPTION: (Taken from the applicant's abstract) The purpose of this application is to request support to provide training in musculoskeletal research to postdoctoral trainees in orthopaedic surgery and to predoctoral trainees in bioengineering in order to prepare these trainees for academic careers. Research areas include the cellular and molecular biology of bone growth, repair, ossification, and maintenance, the mechanism of action of mechanical and electrical perturbation of bone and cartilage cells, the etiology and pathogenesis of tendon and ligament injury, repair, and regeneration, and the mechanics of diarthrodial joints, particularly of the shoulder and elbow. Two postdoctoral and three predoctoral positions are proposed. Candidates for the first postdoctoral slot will be chosen according to the following priority scheme: 1 ) orthopaedic surgeons desiring 2 years of post-residency training in basic musculoskeletal research, 2) M.D.s/Ph.D.s desiring 2 years of training in basic musculoskeletal research, and 3) orthopaedic residents who desire a 1 year experience in musculoskeletal research. Candidates for the second postdoctoral slot will be fellows spending two years on the Shoulder and Elbow Service at Penn. Only the second 'research' year will be supported by the training grant. The predoctoral trainees must be accepted by the Graduate Group in Bioengineering in competition with other candidates and will join the orthopaedic bioengineering program. The primary facility is the McKay Laboratory of the Department of Orthopaedic Surgery, University of Pennsylvania School of Medicine. The multidiscipline McKay Laboratory includes facilities in Biochemistry, Biomaterials, Bioengineering, Biophysics, Computation, Connective Tissue, Electron Microscopy, Histology, Molecular Biology, and Tissue Culture. In addition, extensive laboratories throughout the Penn campus such as those of the Department of Bioengineering are available to the trainees.